// Copyright (c) 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include <stddef.h>
#include <stdint.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <unistd.h>

#include "base/bind.h"
#include "base/bind_helpers.h"
#include "base/files/file_util.h"
#include "base/files/scoped_file.h"
#include "base/location.h"
#include "base/pickle.h"
#include "base/posix/unix_domain_socket_linux.h"
#include "base/single_thread_task_runner.h"
#include "base/synchronization/waitable_event.h"
#include "base/threading/thread.h"
#include "testing/gtest/include/gtest/gtest.h"

namespace base {

namespace {

    TEST(UnixDomainSocketTest, SendRecvMsgAbortOnReplyFDClose)
    {
        Thread message_thread("UnixDomainSocketTest");
        ASSERT_TRUE(message_thread.Start());

        int fds[2];
        ASSERT_EQ(0, socketpair(AF_UNIX, SOCK_SEQPACKET, 0, fds));
        ScopedFD scoped_fd0(fds[0]);
        ScopedFD scoped_fd1(fds[1]);

        // Have the thread send a synchronous message via the socket.
        Pickle request;
        message_thread.task_runner()->PostTask(
            FROM_HERE,
            Bind(IgnoreResult(&UnixDomainSocket::SendRecvMsg), fds[1],
                static_cast<uint8_t*>(NULL), 0U, static_cast<int*>(NULL), request));

        // Receive the message.
        std::vector<ScopedFD> message_fds;
        uint8_t buffer[16];
        ASSERT_EQ(static_cast<int>(request.size()),
            UnixDomainSocket::RecvMsg(fds[0], buffer, sizeof(buffer),
                &message_fds));
        ASSERT_EQ(1U, message_fds.size());

        // Close the reply FD.
        message_fds.clear();

        // Check that the thread didn't get blocked.
        WaitableEvent event(WaitableEvent::ResetPolicy::AUTOMATIC,
            WaitableEvent::InitialState::NOT_SIGNALED);
        message_thread.task_runner()->PostTask(
            FROM_HERE, Bind(&WaitableEvent::Signal, Unretained(&event)));
        ASSERT_TRUE(event.TimedWait(TimeDelta::FromMilliseconds(5000)));
    }

    TEST(UnixDomainSocketTest, SendRecvMsgAvoidsSIGPIPE)
    {
        // Make sure SIGPIPE isn't being ignored.
        struct sigaction act = {}, oldact;
        act.sa_handler = SIG_DFL;
        ASSERT_EQ(0, sigaction(SIGPIPE, &act, &oldact));
        int fds[2];
        ASSERT_EQ(0, socketpair(AF_UNIX, SOCK_SEQPACKET, 0, fds));
        ScopedFD scoped_fd1(fds[1]);
        ASSERT_EQ(0, IGNORE_EINTR(close(fds[0])));

        // Have the thread send a synchronous message via the socket. Unless the
        // message is sent with MSG_NOSIGNAL, this shall result in SIGPIPE.
        Pickle request;
        ASSERT_EQ(-1,
            UnixDomainSocket::SendRecvMsg(fds[1], static_cast<uint8_t*>(NULL),
                0U, static_cast<int*>(NULL), request));
        ASSERT_EQ(EPIPE, errno);
        // Restore the SIGPIPE handler.
        ASSERT_EQ(0, sigaction(SIGPIPE, &oldact, NULL));
    }

    // Simple sanity check within a single process that receiving PIDs works.
    TEST(UnixDomainSocketTest, RecvPid)
    {
        int fds[2];
        ASSERT_EQ(0, socketpair(AF_UNIX, SOCK_SEQPACKET, 0, fds));
        ScopedFD recv_sock(fds[0]);
        ScopedFD send_sock(fds[1]);

        ASSERT_TRUE(UnixDomainSocket::EnableReceiveProcessId(recv_sock.get()));

        static const char kHello[] = "hello";
        ASSERT_TRUE(UnixDomainSocket::SendMsg(
            send_sock.get(), kHello, sizeof(kHello), std::vector<int>()));

        // Extra receiving buffer space to make sure we really received only
        // sizeof(kHello) bytes and it wasn't just truncated to fit the buffer.
        char buf[sizeof(kHello) + 1];
        ProcessId sender_pid;
        std::vector<ScopedFD> fd_vec;
        const ssize_t nread = UnixDomainSocket::RecvMsgWithPid(
            recv_sock.get(), buf, sizeof(buf), &fd_vec, &sender_pid);
        ASSERT_EQ(sizeof(kHello), static_cast<size_t>(nread));
        ASSERT_EQ(0, memcmp(buf, kHello, sizeof(kHello)));
        ASSERT_EQ(0U, fd_vec.size());

        ASSERT_EQ(getpid(), sender_pid);
    }

    // Same as above, but send the max number of file descriptors too.
    TEST(UnixDomainSocketTest, RecvPidWithMaxDescriptors)
    {
        int fds[2];
        ASSERT_EQ(0, socketpair(AF_UNIX, SOCK_SEQPACKET, 0, fds));
        ScopedFD recv_sock(fds[0]);
        ScopedFD send_sock(fds[1]);

        ASSERT_TRUE(UnixDomainSocket::EnableReceiveProcessId(recv_sock.get()));

        static const char kHello[] = "hello";
        std::vector<int> send_fds(UnixDomainSocket::kMaxFileDescriptors,
            send_sock.get());
        ASSERT_TRUE(UnixDomainSocket::SendMsg(
            send_sock.get(), kHello, sizeof(kHello), send_fds));

        // Extra receiving buffer space to make sure we really received only
        // sizeof(kHello) bytes and it wasn't just truncated to fit the buffer.
        char buf[sizeof(kHello) + 1];
        ProcessId sender_pid;
        std::vector<ScopedFD> recv_fds;
        const ssize_t nread = UnixDomainSocket::RecvMsgWithPid(
            recv_sock.get(), buf, sizeof(buf), &recv_fds, &sender_pid);
        ASSERT_EQ(sizeof(kHello), static_cast<size_t>(nread));
        ASSERT_EQ(0, memcmp(buf, kHello, sizeof(kHello)));
        ASSERT_EQ(UnixDomainSocket::kMaxFileDescriptors, recv_fds.size());

        ASSERT_EQ(getpid(), sender_pid);
    }

    // Check that RecvMsgWithPid doesn't DCHECK fail when reading EOF from a
    // disconnected socket.
    TEST(UnixDomianSocketTest, RecvPidDisconnectedSocket)
    {
        int fds[2];
        ASSERT_EQ(0, socketpair(AF_UNIX, SOCK_SEQPACKET, 0, fds));
        ScopedFD recv_sock(fds[0]);
        ScopedFD send_sock(fds[1]);

        ASSERT_TRUE(UnixDomainSocket::EnableReceiveProcessId(recv_sock.get()));

        send_sock.reset();

        char ch;
        ProcessId sender_pid;
        std::vector<ScopedFD> recv_fds;
        const ssize_t nread = UnixDomainSocket::RecvMsgWithPid(
            recv_sock.get(), &ch, sizeof(ch), &recv_fds, &sender_pid);
        ASSERT_EQ(0, nread);
        ASSERT_EQ(-1, sender_pid);
        ASSERT_EQ(0U, recv_fds.size());
    }

} // namespace

} // namespace base
